Water cooler



FIG. 1 is a perspective view of the design for the water cooler;

FIG. 2 is a front view thereof;

FIG. 3 is a rear view thereof;

FIG. 4 is a left view thereof;

FIG. 5 is a right view thereof;

FIG. 6 is a top view thereof; and,

FIG. 7 is a bottom view thereof.

The broken lines are for the purposes of illustrating portions of thewater cooler and form no part of the claimed design.

CLAIM The ornamental design for a water cooler, as shown and described.